A caller of a telephone may make a call origination request through a computer terminal or the like. In this case, the computer terminal sends a telephone relay apparatus information that specifies the phone number of an origination telephone terminal (that is, a telephone terminal that a caller uses) and information that specifies the phone number of a destination telephone terminal. In this case, the telephone relay apparatus calls the origination telephone terminal as well as the destination telephone terminal. Further, the origination telephone terminal and the destination telephone terminal perform a phone call process through the telephone relay apparatus.
For example, a Request For Comment (RFC) 3725 describes a third party call control method. According to this method, when a portable terminal instructs the telephone relay apparatus about a call destination through a data communication network, the telephone relay apparatus originates a call to the call destination and the portable terminal that has instructed.
Further, Patent Document 1 describes that the telephone relay apparatus pre-stores identification information of a telephone apparatus that is a call origination, and a phone number of a call destination. When receiving an originating call from the telephone apparatus, the telephone relay apparatus establishes a call connection, and performs a call relay process by reading out the phone number that corresponds to the identification information of the telephone terminal and originating a call to the phone number.